Abstract

A growing body of evidence supports the hypothesis that humans
infer future states of perceived physical situations by propagating noisy
representations forward in time using rational (approximate) physics. In the
present study, we examine whether humans are able to predict (1) the resting
geometry of sand pouring from a funnel and (2) the dynamics of three
substances---liquid, sand, and rigid balls---flowing past obstacles into two
basins. Participants' judgments in each experiment are consistent with simulation
results from the intuitive substance engine (ISE) model, which employs a Material
Point Method (MPM) simulator with noisy inputs. The ISE outperforms ground-truth
physical models in each situation, as well as two data-driven models. The results
reported herein expand on previous work proposing human use of mental simulation
in physical reasoning and demonstrate human proficiency in predicting the
dynamics of sand, a substance that is less common in daily life than liquid or
rigid objects.